Direct brown azo dyes and processes of manufacturing the same



l atented Mar. 25, 1941 UNITED STATES PATENT OFFICE DIRECT BROWN AZODYES AND PROCESSES OF-MANUFACTURING THE SAME No Drawing. ApplicationAugust 2, 1939, Serial No. 287,902

4 Claims.

This invention relates to direct azo colors suitable for dyeing cottonfibres, and especially to a type of such direct tetrakisazo dyes and tomethods of manufacturing the same.

5 Numerous direct azo colors for cotton are known which are in generalsubstantive to other cellulosic fibres, such as regenerated cellulose.The dyeings on cellulose and regenerated cellulose, such as cottonfibres and regenerated cellu- 10 lose rayon fibres have bright shadesand moderate fastness to light. When these dyes are applied tocellulosic fibres which are associated with non-cellulosic fibres thenon-cellulosic fibres are badly stained. Such staining is im- 5 partedto cellulose acetate fibres and other uncolored and differently colorednon-cellulosic fibres. Because of their brightness, low-cost and ease ofapplication, direct azo dyes for cellulosic fibres, such as celluloseand regenerated cellulose 2 are in great demand by the art but it isdesirable to provide such dyes that do not have afiinity for ordeleteriously stain cellulose acetate fibres so that the cellulosicportions of mixtures which contain cellulose acetate can be dyed withoutdeleteriously staining the cellulose acetate portions, and for otherreasons.

It is an object of the present invention to provide improved direct azodyes for cellulosic fibres 30 which do not have the objectionableproperty of deleteriously staining associated uncolored or differentlycolored cellulose acetate fibres. Another object of the invention is toprovide meth ods of preparing the improved dyes. Other 5 objects of theinvention will be apparent from the following description.

The objects of the invention are. attained in general by providing azocompounds of the type X Y Z w u and dyeing the fibres directly 40 fromsolutions of these compounds. In the type formula, X represents ananiline, a naphthylamine, an aniline monoor di-sulfonic acid, anaphthylamine monoor di-sulfonic acid, an aniline monoor di-carboxylicacid or a naphthylamine monoor di-carboxylic acid, in which any of thearyl nuclei may be unsubstituted or substituted once or more than onceby alkyl, alkoxy, aryl, aralkyl, halogen or nitro; Y is an 50unsubstituted amino-naphthol mono or (Ii-sulfonic acid; Z is ameta-diamino benzene represented by the formula R: III-H:

HiN 5 wherein at least one of the Rs is hydrogen and the other two areat least one of a group consisting of hydrogen, alkyl, alkoxy andhydroxy and wherein one of the groups R1 and R3 is hydrogen; w isbenzidine or tolidine; and u is a coupling component of thegroup'consisting of hydroxy benzene carboxylic acids and couplingcomponents which are devoid of sulfonic acid groups consisting of phenylpyrazolones, acetoacetarylides of the benzene and naphthalene serieswhich may be unsubstituted or substituted once or more by alkyl andalkoxy groups and mono-hydroxy benzenes. In the making of thesecompounds the monazo compound X Y is diazotized'and coupled to Z in abasic medium containing an excess of Z over that which couples with thediazo of X Y. This excess of Z in association with X Y- Z constitutes anundesirable constituent in the mixture and it is deleterious to thefinal product when it is present in the free state and subsequentcouplings are made. The coupling medium containing X Y Z and the excessof Z is treated with an extraneous diazotized arylamine containing atleast one sulfonic acid group which couples with the excess of Z andforms combinations which are either removed in subsequent operations orare nondeleterious to the coupling medium and to combinationssubsequently to be made. When the excess of the compound Z is thusdisposed of by coupling, the compound X Y Z is coupled in basic mediumwith the diazo of the monazo compound w u. The compound X Y Z+w u isthen separated from the mixture.

The invention will be more fully set forth in the following moredetaileddescription which includes examples that are given as illustrative 5embodiments of the invention and not as limitations thereof.

' Exam'plei A solution of 24.5. parts b weight. of sodium 59naphthionate was made in 300 parts by weight of water, 11 parts byweight of hydrochloric acid were added in the form of a 30% solution andthe mixture was cooled to 10-l2 C. by adding ice. A 30% solution ofsodium nitrite was added to the mixture as fast as the nitrite wasabsorbed until 6.9 parts have been added. The mixture was diazotized at15 C. for about forty-five minutes. The final mixture containing ayellow suspended solid was acid to Congo red paper.

A basic solution giving a permanent light test on brilliant yellow paperwas made by adding a 30% solution of sodium hydroxide to a slurrycomposed of 34 parts by weight of the monosodium-salt of Z-amino 8naphthol 3,6 disulfonic acid in 300 parts by weight of water. Thissolution was made more basic by'adding- 32 parts by weight of sodiumcarbonate and was cooled to 0 C. by adding ice.

The first coupling was made by running about 95% of the above describeddiazo mixture into the basic solution of the sodium salt of Z-amino-8-naphthol-3,6-disulfonic acid with stirring during 15 to 20 minutes.The balance of the solution was then added to the mixture giving aslight excess of the salt over that required for coupling with all thediazo present. The mixture was then stirred another 15 to 20 minuteswhilst maintaining the temperature at 0 to 5 C.

The resulting monazo combination in the mixture is represented by theformula NaO as N=N NH2 NaO S SOaNa The above monazo compound wasprepared for diazotization by adding a 30% solution of hydrochloric aciduntil 27.5 parts of hydrochloric acid had been added and the mixture wascooled to 0 C. by adding ice. The monazo compound was diazotized byadding to the acidified mixture a 30% solution of sodium nitrite until6.9 parts of sodium nitrite had been added and a slight excess ofnitrite was present over that required for diazotization. Diazotizationwas completed in about one-half hour whilst maintaining the temperatureat 0 to 5 C. When completed the excess of nitrous acid was neutralizedby adding a small amount of aniline-2,5-disulfonic acid in solution.

The second coupling was made at 0 to 5 C. by adding the above diazo to abasic solution of 1,3-diaminobenzene With agitation of the mixture. Thebasic solution of the coupling component was made by mixing 11 parts of1,3- diaminobenzene with parts of water and heating to 50 to 55 C. untilcomplete solution was attained. This solution was then cooled to 0 C. byadding ice and 75 parts of sodium carbonate were added. The mixturecontaining the cooled diazotized monazo compound described above wasslowly added to the cooled basic solution of 1,3-diaminobenzene andcoupling was allowed to proceed with vigorous agitation whilstmaintaining the temperature at about 0 to 5 C. The coupling mediumshould give a strong test for alkalinity on brilliant yellow paper and adistinct excess of 1,3-diamino benzene over that required to couple withthe monazo compound SOaNa NaO aS- N=N NaOaS The excess of 1,3-diaminobenzene was next removed by coupling the excess with diazotizedaniline-2,5-disulfonic acid in a medium of regulated pH value asfollows:

Firstly, the solution of diazotized aniline2,5- disulfonic acid was madeby stirring 7.5 parts of the sulfonic acid in parts of water, cooling to0 C. with ice, adding 2.15 parts of hydrochloric acid as a 30% solutionthereof and then slowly adding a 30% sodium nitrite solution as rapidlyas the nitrite was absorbed over a period of about one-quarter houruntil a slight excess of nitrite over that required for diazotizationwas present and the compound was diazotized. The temperature wasmaintained at 0 to 5 C. Finall the excess of nitrite was removed byadding a small amount of aniline-2,5-disulfonic acid.

The mixture containing the product of the second coupling was now madeneutral to brilliant yellow paper and acid to blue litmus paper byadding about 47 parts by weight of hydrochloric acid as a 30% solutionthereof, and 12.3 parts of crystalline sodium acetate were dissolved inthe mixture. This mixture was then violently agitated and one-half ofthe above described solution of diazotized aniline-2,5- disulfonic acidwas added. At this point the medium gave no test for free1-3-diaminobenzene when spotted with tetrazo dianisidine but a furtheraddition of the diazo was required. The end point was indicated by thefollowing control test for cellulose acetate stain.

A test sample of about 3 cubic centimeters of the coupling medium wasdiluted to 50 c. c. with water and 1 c. c. of 2 normal sodium carbonatewas added. 4 drops of a solution of para-nitroaniline diazo (.1 mol perliter) were added with stirring and the mixture was heated to 50 C. A 4inch piece of cellulose acetate skein was added and the mixture wasslowly heated to 90 C. After removing the skein and washing, the skeinhad a heavy pink to red stain. This test was applied after successivesubsequent additions of diazotized aniline-2,5-disulfonic acid and smalladditions of diazotized aniline-2,5-disulfonic acid were madesuccessively until there was no decrease in the depth of the celluloseacetate stain as affected by the last small addition.

In this case one-third of the remaining solution ofaniline-2,5-disulfonic diazo was added very slowly over one-quarter hourto the coupling medium. The cellulose acetate stain test was applied andthen other small portions of the diazo solution were added with testingfor cellulose acetate stain after each addition. This was continueduntil all the excess of 1-3-diaminobenzene was coupled with diazotizedaniline-2,5-disulfonic acid and the last two tests showed like stains.

During the latter additions the coupling medium was repeatedly testedfor pH value and was maintained at a pH value of about 5.

After the addition of the last portion of diazotizedaniline-2,5-disulfonic acid the coupling mixture was stirred aboutone-half hour.

The disazo combination contained in the coupling medium was next coupledwith the diazotized monazo compound obtained by coupling tetrazotizedbenzidine with salicylic acid. The coupling medium containing thedescribed disazo combination and with the excess of 1,3-diamino-'benzene rendered inactive was made basic by adding 22 parts of sodiumcarbonate and cooled to 01 C. A previously and freshly preparedsuspension o-f benzidinesa1icylic acid diazo was cooled'to 0 to 5 C.with stirring until the coupling was completed which required about 5hours.

The tetrakisazo compound was separated from the coupling medium byheating to C. to 0., adding about 15% by weight of the medium of sodiumchloride, stirring 30 to 40 minutes, adding hydrochloric acid untilthesolution was acid to litmus and then stirring one-half hour. The dyewhich was practically all out of solution, was filtered oil and dried atC. .to C. in an oven.

The product was a dark brown powder, soluble in water, giving a deepbrown direct dyeing on cotton and rayon. The product is represented bythe formula 0 E 17111 NaO3S N=N N=N-ONH2 NaOzS SOaNa I C O ONa Thesolution of diazotized benzidinesalicylic acid which was used in thefinal'coupling was prepared as follows. An alkaline solution of sodiumsalt of salicylic acid was first made by mixing 12.5 parts of salicylicacid in 300 parts of water, adding 3.6 parts of sodium hydroxide andstirring until a clear solution was formed. The solution was then madedistinctly basic by adding 9 parts of sodium carbonate. A solution oftetrazotized, benzidine was also prepared as follows. A mixture of 14.8parts of benzidine hydrochloride and 350 parts of water was made into aslurry,

acid solution was then added to the tetrazo solu-' tion as rapidly aspossible and then parts of a sodium carbonate solution containing 11parts of sodium carbonate per parts of water are added. The mixture wasmaintained at a temperature of 0 C. to 5 C. and strongly alkaline tbrilliant yellow paper until coupling was complete. The couplin wasconsidered complete when a spot test with alkaline1,8-amino-naphthol-3,6-disulfonic acid solution showed a faint pink.This required about 30 to 40' minutes. There was present a slight excessof salicylic acid as shown by testing with ferric chloride solution.

The dye describedin the foregoing example was dissolved in water in theproportion of 0.25 gram per 200 cubic centimeters of water and heated toF. A 10 g. cotton skein and a 2 g. cellulose acetate skein were tiedtogether and entered into the bath. To 200 c. c. of bath 2 g. ofGlaubers salt were added. The bath was heatedto l t- F. and held at thistemperature for 45 minutes.

The skeins were removed, washed well in water and dried. The cottonskein was dyed a true deep brown shade whereas the cellulose acetateskein remained practically white.

Another disazo compound was prepared from the same materials as wereused for preparing the compound of Example'l. The compound was preparedin exactly the same way as the compound of Example 1 was prepared exceptthat the coupling medium containing the disazo dye was not treated todispose of the excess of free compound Z. A dyebath made with thiscompound gave a distinct deleterious brown stain to a cellulose acetateskein.

The invention is further illustrated by the following compounds whichwere prepared similarly to the compound described in Example 1. Thesecompounds did not harmfully stain cellulose acetate when prepared by theabove described method as they did when prepared by the methodsdisclosed'in the prior art.

Example Combination Shade 2 2-amino-naphthalone-6,8-disulphonic-acid2-amino-5-naphthol-7-s11lionic acid 1,3-diamino- Brown.

benzene benzidine salicylic acid.

3 aniline-2,5-disulfonic acid 2-amino-8-naphthol-3,ti-disulfonic-acid1,3-diamino-benzene Do.

benzidine salicylic acid.

4 3methyl-6-methoxy-aniline 2-amino-8-naphthol-3,(i-disulfonic-acid1,3-diamino-benzene Do.

benzidine salicylic acid.

5 4-chloro-aniline-3-sulfonic-acidZ-amino-B-naphthol-B,fi-dilsufonic-acid 1,3-diamino-benzcne Do.

(- be zidine salicylic acid. I

6 Naphthlonic acid 2-amino-8-naphthol-3,6-d1sulfonic-ac1d1,3-d1amino-4-methyl-benzene D0.

benzidine salicylic acid. 7

7 l-naphthyllamine1 2amino8-naphthol-3,6-disulfonic-acid1,3-diam1no-benzene benzidine Do.

) sa lcy 1c aci 8 Naphthionic acid2-amino-8-naphthol-3,fi-disulionic-acid 1,3-diamino-benzene benzidineDo.

salicylic acid.

9 Naphthionic acid 2-amino-8-naphthol-3,6,disl11f0ni0-ac1d1,3-diammo-bcnzene ebenzidine Do.

cresotinic-acid.

10.". Nap1hth1ipnic geld 2-amino-5-naphtho1-7-suli'onic-ac1d1,3-diamino-benzene benzidine Do.

sa my 10 am l1 sulanillic acidi 2-amino-8-naphtho1-3,fi-disulfonic-acid1,3-diamino-benzene benzidine Do.

s icy 10 am l2 Aniljle 2-amino-8-naphthol-3,6-disulfonic-acid1,3-diamino-benzene benzidine salicylic Do.

' acl In preparing the compounds of the present invention otherdiazotized compounds can be used as the extraneous reagent instead ofdiazotized aniline-2,5-disulfonio acid and to the same effect inremoving the excess of uncoupled com-' pound Z from the mixturecontaining the disazo compound X Y Z. The aniline, 2-, 3- and 4-sulfonic acids, aniline-2,5-disulfonic acids, 1- naphthylamine-iandG-sulfonic acids, l-naphthylamine3,6-disulfonic acids andZ-naphthylamine-6,8-disulfonic acids, any of which are eitherunsubstituted or are substituted by other groups can be used. In thespecification and claims reference to such sulfonic acids means thesubstituted as well as the unsubstituted acids, unless otherwisedenoted. As illustrations of such other compounds are mentionedsulfanilic acid, metanilic acid, 4-ch1oro-aniline-3-sulfonic acid,naphthionic acid, l-amino-naphthalene-6- sulfonic acid,2-amino-naphthalene-6,8-disulfonic acid,1-amino-naphthalene-3,6,8-trisulfonic acid,4-amino-3-methyl-benzene-sulfonicacid, Z-amino 3,5dimethyl-benzene-sulf0nicacid, 2-aminoi-methyl-5-chloro-benzene-su1-ionic-acid, 2-methoxy-5-amino-benzene-sulfonicacid,2-amino-5-nitro-benzene-sulfonic-acid, 2-amino-4-nitro-S-methyl-benzene-sulfonic acid, Z-amino -5- methyl-benzene-1,4- disulfonic-acid, 2-bromo-5-amino benzene 1,3 disulfonic-acid andl-amino-Z-methoxy-naphthalene-6-su1fonicacid. In this operation the pHvalue of the medium is preferably maintained at about 5 but pH valuesover a range of about 4 to about 9 is generally convenient. However, theextraneous reagent can be used in any acidic or basic medium which isnot so acidic as to prevent the coupling with the excess of component Z,and is not so basic as to cause appreciable coupling with the compound XY Z. The pH value may be adjusted if necessary after each addition ofthe diazo by adding a base, such as sodium carbonate.

As illustrative of other compounds which can be used for the X componentare mentioned 1)- nitro-aniline, para-amino-benzoic acid, aniline-2,5-carboxylic acid, l-amino-naphthalene-7-carboxylic acid,2-amino-naphthalene-6,8-dicarboxylic acid and any of the extraneousagents hereinbefore mentioned. These compounds can be unsubstituted orthey may be substituted by groups, such as alkyl, alkoxy or halogen.

As other Y compounds l-amino-5-naphthol-7- sulfonic acid,2-amino-8-naphthol-6-sulfonic acid, and1-amino-8-naphthol-4,6-disulfonic acid are mentioned as illustrative,but any 1- or 2-arnino-naphthol sulfonic acid can be used as the Ycomponent which has hydroxy in the 5 or 8 position. A second sulfonicacid group may be in any unoccupied position of the ring which issubstituted by amino when this component is an amino-naphthol disulfonicacid.

The preferred embodiments of the combination X+Y contains at least twosulfonic acid groups.

As illustrations of other Z compounds ,2-4-diamino-toluene,2-4-diamino-anisole, 2 6 diamino-toluene, 2,6-diamino -4-methoxy-toluene, 2-4diamino-phenol and 2-methoxy-3,5-diamino toluene arementioned but any other meta-diamino benzene as indicated by the generalformula can be used.

Illustrations of other coupling components, u are1-phenyl-3-methyl-5-pyrazolone, 1-phenyl-5- pyrazo1one-3-carboxylicacid, aceto-acetanilide, p-methyl-aceto-aoetanilide,alpha-aceto-aceticnaphthanilide, phenol and o-cresol.

'The terms alkyl and alkoxy as used in the specification and claimsrefer to straight and branched chain aliphatic groups having 1 to 4carbons and the corresponding alkoxy groups. Aralkyl refers toalkyl-aryl groups of which alkyl is the bridging group and aryl isbenzene, such as benzyl. The substituent aryl refers to benzene andnaphthalene and halogen refers to chlorine, bromine, iodine andfluorine. The indicated substituents of the aryl nuclei may besubstituted in any position or positions which do not interfere withdiazotization or coupling.

While some of the improved compounds of the invention give a slightstain on cellulose acetate fibres, the stain is so slight as to benon-deleterious. The invention imparts utility to the dyes which wasnon-existent in prior art types since the dyes can be used in manycombinations of fibres where dyes prepared by prior art methods wereunsatisfactory.

From the foregoing disclosure it will be recognized that the inventionis susceptible of modification without departing from the spirit andscope thereof and it is to be understood that the invention is notrestricted to the specific illustrations herein set forth.

We claim:

1. In the process of manufacturing an azo compound represented by theformula in which X is one of a group consisting of an aniline, anaphthylamine, the monoand disulfonic acids of said anilines andnaphthylamines, aniline monoand di-carboxylic acids, naphthylaminemonoand di-carboxylic acids, and the derivatives of said compounds ofthe benzene and naphthalene series in which any aryl nuclei issubstituted by at least one of a group consisting of hydrogen, alkyl,alkoxy, aralkyl, halogen and nitro; Y is one of a group consisting ofamino-naphthol monoand di-sulfonic acids; Z is a meta-diamino-benzenerepresented by the formula wherein at least one of the E5 is hydrogen,the other Rs are at least one of a group consisting of hydrogen, alkyl,alkoxy and hydroxy, and wherein one of the groups R1 and R3 is hydrogen;w is one of a group consisting of benzidine and tolidine; and u is oneof a group of coupling components consisting of hydroxy benzenecarboxylic acids and coupling components which are devoid of sulfonicacid groups from the group consisting of phenyl pyrazolones,aceto-acetarylides of the benzene and naphthalene series, andmono-hydroxy benzenes; the steps which comprise diazotizing a compoundX-+Y and coupling with Z in alkaline medium; adding to the couplingmedium a diazotized primary arylamine of the benzene and naphthaleneseries which contains at least one sulfonic acid group, said additionbeing made until the excess of free compound Z in said mixture iscoupled to the added diazo and the medium will give no test foruncoupled compound Z; making the coupling medium basic; and thencoupling the compound X Y Z with a diazotized product of coupling w u.

2. In the process of manufacturing an azo compound represented by theformula in which X is one of a group consisting of an aniline, anap-hthylamine, the monoand disulfonic acids of said anilinesandnaphthylamines, aniline monoand di-carboxylic acids, naphthylaminemonoand di-carboxylic acids, and the derivatives of said compounds ofthe benzene and naphthalene series in which any aryl nuclei issubstituted by at least one of a group consisting of hydrogen, alkyl,alkoxy, aralkyl, halogen and nitro; Y is one of a group consisting ofaminonaphthol monoand di-sulfonic acids; Z is a meta-diamino-benzenerepresented by the formula i 7 C} I R; Ra

wherein at least one of the Rs is hydrogen, the other Rs are at leastone of a group consisting of hydrogen, alkyl, alkoxy, and hydroxy, andwherein one of the groups R1 and Re is hydrogen; w is one of a groupconsisting of benzidine and tolidine; and u is one of a group ofcoupling components consisting of hydroxy benzene carboxylic' acids andcoupling components which are devoid of sulfonic acid group from thegroup consisting of phenyl pyrazolones, aceto-acetarylides of thebenzene and naphthalene series, and mono-hydroxy benzenes; the stepswhich comprise diazotizing a compound X Y which contains at least twosulfonic acid groups and coupling with Z in alkaline medium; adding tothe coupling medium a diazotized compound of the group consisting ofaniline 2-, 3-, and 4-sulfonic acids, aniline 2,5-disulfonic acids,l-naphthylamine-- and -6-sulfonic acids, 1-naphthy1amine-3,6-disulfonicacids and Z-naphthylamine-6,8-disulfonic acids, said addition being madeuntil the excess of free compound Z in said mixture is coupled to theadded diazo and the medium will give no test for uncoupled compound Z;making the coupling medium basic; and then coupling the compound X Y Zwith a diazotized product of coupling w u.

3. In the process of manufacturing an azo compound represented by theformula in which X is one of a group consisting of an aniline, anaphthylamine, the monoand disulfonic acids of said anilines andnaphthylamines, aniline monoand di-carboxylic acids, naphthylaminemonoand di-carboxylic acids, and the derivatives of said compounds orthe benzene and naphthalene series in which any aryl nuclei issubstituted by at least One of a group consisting of hydrogen, alkyl,alkoxy,

aralkyl, halogen and nitro; Y is one of a group consisting ofamino-naphthol monoand di-sulfonic acids; Z is a meta-diamino-benzenerepresented by the formula wherein at least one of the Rs is hydrogenand the other Rs are at least one of a group consisting of hydrogen,alkyl, alkoxy, and hydroxy, and wherein one of the groups R1 and R3 ishydrogen; w is one of a group consisting of benzidine and toli-dine; andu is one of a group of coupling components consisting of hydroxy benzenecarboxylic acids and coupling components which are devoid of sulfonicacid groups from the group consisting of phenyl pyrazolones,acetoacetarylides of the benzene and naphthalene series, andmono-hydroxy benzenes; the steps which comprise diazotizing a compoundX- Y which contains at least two sulfonic acid groups and coupling Z inalkaline medium containing an excess of Z over that required forcoupling; adjusting the coupling medium to a pH value of at least 4 andnot more than 9; adding diazotized aniline-2-5-disulfonic acid to thecoupling medium until the excess of free compound Z is coupled to theadded diazo and the medium will give no test for uncoupled compound Z;making the coupling medium basic; and then coupling the compound X Y Zwith a diazotized product of coupling w u.

4. The process which comprises diazotizing the compound represented bythe formula HO QNm M,

(JOONa EIVIMET 1". HITCH. SWANIE S ROSSANDER. CHILES E. SPARKS.

